Method of venting an aerosol dome

ABSTRACT

A method of forming a bead surrounding an opening in one end of a container body by rolling a neck extending from the body to a position where the free edge and an adjacent end portion of the neck overlap an adjacent outer surface of the body. A method contemplates rolling at least one selected portion of the neck to a smaller internal diameter than the internal diameter of the remainder of the neck so as to space a segment of the free edge from the outer surface of the body to provide a vent opening placing the internal area of the bead in communication with the surrounding outside area. In one embodiment, the smaller diameter portion of the bead is formed by producing projections extending above the free edge of the neck. A second embodiment contemplates outwardly deforming a selected portion of the neck and, in a third embodiment, the reduced diameter portion is deformed by inwardly deforming a selected portion of the neck.

United States Patent Miller et al.

[151 3,677,21 l 1 July 18, 1972 METHOD OF VENTING AN AEROSOL DOME [72]Inventors: Stanley J. Miller; James P. Devlthnn, both of Chicago, 111.

[73] Assignee: National Can Corporation, Chicago, Ill. [22] Filed: April13, 1970 [21] Appl. No.: 27,780

[52] U.S. CL ..ll3/l2lAA, 113/1201 [51] lnLCl. ..llZld 51/00 [58]FleldolSearch ..ll3/1l6A,120K,120V,120Y,

113/120 AA, 121 AA, 121 C, 120 P; 220/44 R, 74

[ References Cited UNITED STATES PATENTS 2,352,251 6/1944 Calleson etal. ..220/44 2,629,421 2/1953 Ayres .....220/44 1,728,533 9/1929Fenn.... .....220/44 1,766,173 6/1930 Hills ..220/44 1,950,327 3/1934Punte ..113/121 C 3,243,075 3/1966 Reinke ..220/44 3,028,039 4/1962Clark ..220/44 3,468,452 9/1969Khoury................................... 220/67 PrimaryExaminer-Charles W. Lanham Assistant Examiner-Michael J. KeenanAnomey-Robert J. Doherty [57] ABSTRACT A method of forming a beadsurrounding an opening in one end of a container body by rolling a neckextending from the body to a position where the free edge and anadjacent end portion of the neck overlap an adjacent outer surface ofthe body. A method contemplates rolling at least one selected portion ofthe neck to a smaller internal diameter than the internal diameter ofthe remainder of the neck so as to space a segment of the free edge fromthe outer surface of the body to provide a vent opening placing theinternal area of the bead in communication with the surrounding outsidearea. In one embodiment, the smaller diameter portion of the bead isformed by producing projections extending above the free edge of theneck. A second embodiment contemplates outwardly deforming a selectedportion of the neck and, in a third embodiment, the reduced diameterportion is deformed by inwardly deforming a selected portion of theneck.

11 Cllllm, 12 Drawing Figures Patented July 18, 1972 3,677,211

2 Sheets-Sheet 1 Patented July 18, 1972 3,677,211

2 Sheets-Sheet 3 METHOD OF VENTING AN AEROSOL DOME BACKGROUND OF THEINVENTION The present invention relates generally to containers and moreparticularly to an improved method for forming a bead adjacent the openend of a container body.

In the formation of containers which are subsequently utilized fordispensing liquids through the use of a propellant, it has becomecustomary to produce and end on the container body which defines anopening for receiving a mounting cup for a valve. The opening issurrounded by a bead or curl that serves as a support for the mountingcup which is crimped to the container end. The container end isgenerally referred to as an aerosol dome which is formed separately andwhich is sealed to the main body of the can with a double seam.

One of the problems encountered in a container of this type is that manytimes propellant and product are forced into the interior of the beadduring a filling operation. In one type of filling or chargingoperation, it is common to cover the entire domed end of the containerwith a charging head before the mounting cup for the valve is crimped tothe dome. The charging head is in engagement with the dome at a pointspaced from the bead or curl surrounding the open end of the dome. Thecharging head is utilized first for producing a vacuum within thecontainer and, subsequently, for introducing pressurized propellant andproduct between the mounting cup and the domed end of the container.After the container is filled, the mounting cup is crimped to the end ofthe container. During such a filling operation, which is generallyreferred to as under-the-cap" filling, there is a tendency forpropellant and produce to be forced into the interior of the curl. Manytimes the propellant and product are trapped in the bead after thecrimping operation has been completed.

After the container has been pressure filled and the mounting cup hasbeen scaled within the opening of the dome, it is customary to test thecontainers for "leakers" by immersing the entire container into a heatedwater bath. During such testing operation, the propellant within thehead, which is in a gaseous state at atmospheric pressure and roomtemperature, tends to escape and produce bubbles in the bath resultingin the false interpretation that the container is a leaker," when, inreality, the container is of sound construction and no leakage ofproduct from within the container itself has taken place. In otherinstances, the product may be forced out of the head while the containeris on display, again indicating that the container is leaking.

Thus, there is a need for a simple and effective method for venting thebead of an aerosol dome.

BRIEF SUMMARY OF THE INVENTION The present invention contemplates amethod for forming a vented bead surrounding the open end of a containerbody. The bead or curl surrounding the opening of the container body isproduced by rolling a neck extending from the body to a position wherethe free edge and an adjacent end portion of the neck overlap anadjacent outer surface of the body to produce a closed area having apredetermined internal radius. At least one circumferential portion ofthe bead is rolled to a reducing radius adjacent the free edge so thatthe overlapped portion of the bead forming part of the reducing radiusportion is spaced from the adjacent outer surface of the container body.The reducing radius or substantially spiral portion is formed byproducing at least one irregular contour on the free edge of the neck,which extends above the body of the container end, and thereafterengaging the free edge with a curling surface having a constant radiusto roll the free edge to the overlapping relation. The longitudinalportion of the neck adjacent the irregular contour is rolled to reducingradius smaller than the predetermined constant radius of the remainderof the head. In the device of my invention the free edge isuninterrupted in configuration along the major circumferential portionthereof by bends or irregular contours of any type. The bead of thefinished container has an appearance essentially the same as that of acompletely uniform head.

One method for produing the irregular contour is to form at least oneprojection extending above the free edge, which is placed in engagementwith the curling surface before the remainder of the body and results ina reducing radius adjacent the free edge or reduced diameter portionalong a small circumferential portion of the bead.

In an alternate embodiment, the irregular contour of the free edge isproduced by outwardly deforming a vertical column portion of the neckand subsequently engaging the free edge of the neck with the curlingsurface. In this embodiment, the outwardly deformed column will again berolled to a reducing radius adjacent the free edge.

In the third embodiment, the irregular contour on the free edge of theneck is produced by inwardly deforming a column longitudinally of theneck which will initially contact the curling surface and result insubstantial areas on opposite sides of the vertical column being curledto reduced diameter portions.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS FIG. I shows afragmentary side elevation view of the container end constructed inaccordance with the present invention and having a mounting cup andvalve secured therein;

FIG. 2 is an enlarged fragmentary view of the free end of the containershown in FIG. 1;

FIG. 3 is a perspective view of the neck portion which ultimately formsthe bead shown in FIG. 2;

FIG. 4 shows a vertical sectional view through one side of the neckshown in FIG. 3 and showing the initial engagement of the free edge ofthe neck with a curling surface;

FIG. 5 is a view similar to FIG. 4 showing the intermediate stage of thepartially curled neck;

FIG. 6 is a vertical sectional view taken generally along line 6-6 ofFIG. 2 and showing the final configuration of the vented bead;

FIG. 6a is an exploded fragmentary view of FIG. 6;

FIG. 7 is a view similar to FIG. 3 showing an alternative method ofproducing an irregular contour on the neck;

FIG. 7a is a view similar to FIG. 5 showing the intermediate stage ofcurling the neck of FIG. 7;

FIG. 8 is a fragmentary side elevational view of the modified aerosoldome;

FIG. 9 is a further embodiment of the neck similar to FIG. 3; and

FIG. 10 is a view similar to FIGS. 5 and 70 showing the intermediatestage of the neck disclosed in FIG. 9.

DETAILED DESCRIPTION While this invention is susceptible of embodimentin many different forms, there is shown in the drawings and will hereinbe described in detail one specific embodiment, with the understandingthat the present disclosure is to be considered as an exemplification ofthe principles of the invention and is not intended to limit theinvention to the embodiment illustrated.

FIG. I of the drawings discloses an aerosol dome 10 constructed inaccordance with the present invention and secured to the upper end of acylindrical body or container 12 through a sealed joint 14, which may bein the form of a commercially known double seam.

The upper end of the dome 10 has an opening 16 which is surrounded by abead or curl 18. A mounting cup 20 support-.

ing a discharge valve 22 is received in the opening 16 with a downwardlyopening channel 17 secured to the bead 18, as by crimping or outwardlydeforming selected areas 24 into engagement with the internal surface ofthe container end.

As was indicated above, when utilizing "under-the-cap" filling methodfor filling the container, it is customary to loosely insert themounting cup 20 having the valve 22 therein into the open end of thecontainer and thereafter to place a charging head over the entirestructure with the lower edge of the charging head engaging the outersurface or wall of the dome I0 at the point outwardly spaced from thehead or curl. A

vacuum is then produced in the container and the high pressurepropellant, in liquid form, and product are forced into the containerbetween the adjacent surfaces of the head 18 and the cooperating channell7 of the mounting cup 20. When the container 12 has been filled withthe desired amount of propellant and product, the mounting cup 20 iscrimped, as at 24, and sealed to the upper end of the dome 10. Such afilling operation many times results in the trapping of propellantand/or product within the internal area of the bead 18, which isundesirable for the reasons set forth above.

According to the broadest aspect of the present invention, the head 18is formed by rolling a cylindrical upstanding neck 30 to a positionwhere the free edge of the neck overlaps an adjacent outer surface ofthe dome 10. The neck is rolled to produce a closed area 28 having aninternal diameter or a substantially constant internal radius. At leastone selected portion of the neck is rolled to a smaller diameter thanthe diameter of the remainder of the neck to thereby space a portion ofthe free edge from the adjacent outer surface of the dome or containerend and provide a vent opening for the internal area of the bead.

Stated another way, at least one small circumferential portion of theneck is rolled to a reducing radius adjacent the free edge so as toproduce a substantially spiral cross-sectional configuration. Thesmaller or reduced radius portion of the internal area of the bead isformed by initially producing at least one irregular contour on the freeedge of the neck which is ultimately rolled or displaced to produce thebead 18. Subsequently, the free edge of the neck is engaged with acurling surface having a constant radius to displace the neck outwardlyand form a bead having an internal radius with the free edge being inoverlapping relation to the outer surface of the container. Theirregular contour of the free edge will cause at least the end area of alongitudinal portion of the neck to be displaced to a smaller radiusthan the remainder of the neck and, thus, space the free edge of thislongitudinal portion from the outer surface of the container body end.

In the embodiment illustrated in FIGS. 1-6, prior to attachment of thedome to the container body 12, an upwardly extending cylindrical neck 30extends from the main body of the done ID to define a free upper edge32. An irregular contour of the free upper edge in the initialembodiment is produced by projections 34 which extend above the freeedge. The projections 34 may be formed simultaneous to the formation ofthe free edge 32, which is normally accomplished by stamping an openinginto a cup shaped member extending above the main portion of the domel0. Alternatively, the projections 34 may be formed as a separateoperation, as by weld ing small beads or other protrusions to extendabove the surface or free edge 32.

In the embodiment illustrated in F168. 26, it is desirable that theprojections be located within the confines of the inner and outersurfaces of the neck 30. The bead 18 is thereafter formed by engagingthe free edge 32 of the neck 30 with a curling surface 36 formed in acurling die having interconnected portions 37 and 38. The curlingsurface takes the form of a downwardly opening recess formed in the diesections 37 and 38 with the base of the recess defining an arcuatesurface having a constant radius.

The actual curling or displacement of the cylindrical neck 30 isaccomplished by relative movement between the curling surface 36 and theneck 30. As is clearly shown in FIG. 4, the initial contact of the upperedge 32 with the curling surface 36 is through the upwardly extendingprojections 34. These upwardly extending projections will thus followthe contour of the curling surface 36 and will initially cause outwarddeformation of a small circumferential area 40, which is in longitudinalalignment with the projection 34. AFter this initial deformation oroutward displacement of the portion 40 of the neck, the remainder of thefree edge 32 will be placed in contacting engagement with the curlingsurface, as shown in FIG. 5, and will ultimately be displaced or curledto the configuration shown in FIG. 6. In the final configuration shownin FIG. 6, it

will be noted that the free edge 32 and an adjacent end portion of theneck 30 are in overlapping relationship with the outer surface 42 of thedome 10. Furthermore, a cross-sectional area through any portion of thebead 18 will show that the neck has been rolled or displaced to a closedarea of substantially cylindrical cross-sectional configuration having asubstantially constant internal diameter or radius. However, thelongitudinal portions of the neck which are in alignment with theprojections 34 will be rolled or displaced in a manner to produce areducing internal radius adjacent the free edge. This will result inhaving the portions 34 of the upper free edge 32 spaced from theadjacent outer surface 42 of the body of the container to produce anopening 44 as is clearly illustrated in FIG. 6a. This will place theinternal area of the head in communication with the surroundingatmosphere at all times. Thus, any gaseous propellant or product, whichmay be in the internal area of the bead after a filling operation, canreadily escape through the openings 44 defined by the respective reduceddiameter portions 40.

While any number of such projections 34 may be circumferentially spacedalong the free edge 32, it is desirable that the respective projectionsbe formed in diametrically opposed pairs on the free edge 32 of thecylindrical neck 30. The diametrically opposed pairs will equalize theforces which are encountered by the neck 30 during the initialdeformation of the longitudinal column portions of the neck which arebelow each of the respective projections 34.

An inspection of FIG. 2 shows that the circumferential extent of thereduced diameter portion is extremely small and may result in what maybe termed a pinpoint" opening 44. However, it will be appreciated thatonly a small opening is necessary for the venting of the propellant,which is in a gaseous state when it is at room temperature andatmospheric pressure, or the product.

A slightly modified embodiment of the present invention is disclosed inFIGS. 7 and 8 in which the upper free edge 32a of the neck 30 has anirregular contour produced by outwardly deforming selected portions ofthe neck 30. ln the embodiment illustrated in FIG. 7, first and secondoutwardly deformed columns 50 are produced at diametrically locatedpoints on the neck. It has been determined that the outwardly deformedcolumns will result in a final configuration of the bead or curl verysimilar to the bead shown in the previous embodiment. While thisphenomenon is not completely understood, it is believed to result, atleast in part, from the fact that during initial engagement and curlingof the internal surface of the major portion of the neck, the outwardlydeform ed columns will remain in substantially columnar form as shown inFIG. 7a. This will cause the crest portions of the columns to engage thecurling surface at points transversely spaced from the point ofengagement of the remainder of the internal surface of the neck.

The engagement of the crests at an angularly related area of thesurface, spaced from the tangential point of contact of the remainder ofthe surface of the neck will cause at least the upper end portion of thecolumns to be rolled to a reducing radius similar to the embodimentshown in FIGS. 245. As the distance from the free edge 32a of the neck30a increases the internal stresses tending to maintain the columns incolumnar form will be overcome by the internal forces developed in theneck during the rolling process.

Alternatively, it may be that at least the upper end of the outwardlydeformed column will remain in its outwardly deformed condition duringthe rolling process. It is believed that this condition results from theexcessive material as well as the additional strength of the outwardlydeformed column.

During the rolling process, as the distance from the free edge 32aincreases, the forces tending to return the outwardly deformed columninto alignment with the main body of the neck likewise increases. Thiswill result in the outwardly deformed column gradually disappearing asthe spacing from the free edge of the neck increases.

In either event, the final configuration of the column portions of theneck will be substantially identical to the projection portions of theneck in the principal embodiment. That is to say the columns will berolled to a cross-sectional configuration having a minumun radius at thefree edge with a gradually increasing radius as the distance from thefree edge increases and ultimately the radius of the column portionswill equal the radius of the remainder of the rolled bead or curl. Thefinal configuration of each of the column portions of the head will be aspiral configuration in one segment adjacent the free edge and a secondsegment having a radius equal to the corresponding segment of theremainder of the neck.

The final configuration of the bead will have "pinpoint" openings orapertures 44a (FIG. 8) of small circumferential extent similar to thatdiscussed in connection with the embodiment of FIGS. 2-6. As in theprevious embodiment, the remainder of the free edge 32a and an adjacentportion will be in contacting engagement with the outer surface of thedome.

A further modified embodiment of the present invention is disclosed inFIGS. 9 and 10 wherein the irregular contour of the upper free edge 32bof the neck 30b is produced by inwardly deforming diametrically opposedportions 60. The diametrically opposed portion 60 extends substantiallythe length of the neck 30b and merge with the main body of the neckalong lines generally designated by the reference numeral 62. In theembodiment of FIGS. 9 and 10, the curling surface 36 has an inclinedportion 64 formed on the lower inner edge thereof.

During the rolling or displacement of the neck 3%, the crest portions ofthe respective columns 60 will initially engage the inclined surface 64to be outwardly deformed. [t has been found that in some instances theinwardly deformed columns will deform outwardly to produce a single pinpoint openings similar to openings 44a while in other instances the rootportions 62 of the respective columns 60 will be deformed outwardly ofthe remainder of the edge 32b. Subsequently, the main portion of theupper edge 32b will engage the curling surface 36 and will produce arolled bead, similar to head 18a.

in the final configuration of the curled bead, either the free end ofthe crest portions or root portions of the columns 60 will be rolled toa reduced diameter and will result in a bead configuration similar thebeads 18 and 180. While the phenomenon of the formation of the reducingradius in this embodiment is not clearly understood, it is believed thatthe reversal of the position of the upper edges of the columns relativeto the main portion of the neck results from the internal forcesdeveloped during the formation of the column 60. In cases where the rootportions 62 of the neck are rolled to a reducing radius, it is believedthat this results from the resistance of the columns to being deformedto the original position in alignment with the main body of the neck.

in each embodiment, the lower edge of the bead or curl will thus have aserpentine or sinuous configuration of very small amplitude. Also, thelower edge of the bead is disposed directly above an adjacent portion ofthe outer surface of the dome and a major, in fact most all of the loweredge, is in engagement with the dome surface.

Each of the embodiments of the present disclosure are capable of beingincorporated into a conventional method of forming a bead or curl sothat it is only necessary to produce the irregular contour on the freeedge either as part of one of the steps for forming the dome 10 or as aseparate step during the forming process. ln all embodiments, the ventedbead is formed by obstructing the normal flow of metal of the neckduring the curling process.

We claim:

l. in a method of forming a vented bead surrounding the opening in thedome body of an aerosol container of the type including the step ofrolling the free edge of the neck of said dome body outwardly to producean integral bead having a predetermined internal radius, the improvementcomprising: rolling a major portion of said free edge of said neck to acontactin en agement with the outer surface of said neck, said free e geemg substantially uninterrupted lll configuration along the majorcircumferential portion thereof; and concurrently rolling the remainingminor portion of said free edge of said neck toward, but short ofengagement with, said outer surface of said neck such that the internalradius of said bead along said minor portion is less than saidpredetermined internal radius.

2. A method as defined in claim I, tion of said free edge is produced byfore said neck is rolled.

3. A method as defined in claim 2, in which said neck is deformedinwardly along substantially the entire axial length thereof.

4. A method as defined in claim 3, in which said neck is inwardlydeformed at opposed locations to produce at least two selected free edgeminor portions.

5. A method as defined in claim 2, in which said neck is outwardlydeformed at least adjacent the free edge of said neck.

6. A method as defined in claim I, in which said minor portion of saidfree edge portion is formed by producing projections extending above thefree edge of said neck.

7. A method of producing a vented bead surrounding an opening in acontainer end comprising the steps of producing at least one irregularcontour on the free edge of a neck extending above the container end,said free edge remaining substantially uninterrupted in configurationalong the major circumferential portion thereof; and engaging said freeedge with a curling surface having a constant radius to displace saidneck to a bead having an internal diameter with the free edge inoverlapping relation to the outer surface of the container, saidirregular contour causing a longitudinal portion of said neck to bedisplaced to a smaller diameter to space the irregular contour portionof the free edge from said outer surface and produce a vent for saidbead.

8. A method as defined in claim 7, in which said irregular contour isproduced by deforming a portion of said neck inwardly.

9. A method as defined in claim 7, in which said irregular contour isproduced by outwardly deforming a portion of said neck.

10. A method as defined in claim 7, in which said irregular contour isproduced by forming a projection extending above the free edge.

11. A method of producing a vented bead surrounding an opening in oneend of a container dome body with a free edge in overlapping relation tothe adjacent outer surface of the dome body which comprises the steps ofrolling a minor circumferential portion, commencing at said free edge ofa neck extending above said body, to a substantially spiralconfiguration having an increasing radius; rolling the remainder of saidneck to a predetermined constant radius; continuing said rolling untilthe radius of said spiral equals said predetermined constant radius;and, thereafter, rolling all of said neck to said predetermined constantradius until said free edge is in overlapping relation with the adjacentsurface of said dome body whereby the major portion of said free edge isin contacting relation with said adjacent surface while the free edge ofsaid spiral portion is spaced from said adjacent surface.

I I l i I in which said minor pordeforming the neck be-

1. In a method of forming a vented bead surrounding the opening in thedome body of an aerosol container of the type including the step ofrolling the free edge of the neck of said dome body outwardly to producean integral bead having a predetermined internal radius, the improvementcomprising: rolling a major portion of said free edge of said neck to acontacting engagement with the outer surface of said neck, said freeedge being substantially uninterrupted in configuration along the majorcircumferential portion thereof; and concurrently rolling the remainingminor portion of said free edge of said neck toward, but short ofengagement with, said outer surface of said neck such that the internalradius of said bead along said minor portion is less than saidpredetermined internal radius.
 2. A method as defined in claim 1, inwhich said minor portion of said free edge is produced by deforming theneck before said neck is rolled.
 3. A method as defined in claim 2, inwhich said neck is deformed inwardly along substantially the entireaxial length thereof.
 4. A method as defined in claim 3, in which saidneck is inwardly deformed at opposed locations to produce at least twoselected free edge minor portions.
 5. A method as defined in claim 2, inwhich said neck is outwardly deformed at least adjacent the free edge ofsaid neck.
 6. A method as defined in claim 1, in which said minorportion of said free edge portion is formed by producing projectionsextending above the free edge of said neck.
 7. A method of producing avented bead surrounding an opening in a container end comprising thesteps of producing at least one irregular contour on the free edge of aneck extending above the containEr end, said free edge remainingsubstantially uninterrupted in configuration along the majorcircumferential portion thereof; and engaging said free edge with acurling surface having a constant radius to displace said neck to a beadhaving an internal diameter with the free edge in overlapping relationto the outer surface of the container, said irregular contour causing alongitudinal portion of said neck to be displaced to a smaller diameterto space the irregular contour portion of the free edge from said outersurface and produce a vent for said bead.
 8. A method as defined inclaim 7, in which said irregular contour is produced by deforming aportion of said neck inwardly.
 9. A method as defined in claim 7, inwhich said irregular contour is produced by outwardly deforming aportion of said neck.
 10. A method as defined in claim 7, in which saidirregular contour is produced by forming a projection extending abovethe free edge.
 11. A method of producing a vented bead surrounding anopening in one end of a container dome body with a free edge inoverlapping relation to the adjacent outer surface of the dome bodywhich comprises the steps of rolling a minor circumferential portion,commencing at said free edge of a neck extending above said body, to asubstantially spiral configuration having an increasing radius; rollingthe remainder of said neck to a predetermined constant radius;continuing said rolling until the radius of said spiral equals saidpredetermined constant radius; and, thereafter, rolling all of said neckto said predetermined constant radius until said free edge is inoverlapping relation with the adjacent surface of said dome body wherebythe major portion of said free edge is in contacting relation with saidadjacent surface while the free edge of said spiral portion is spacedfrom said adjacent surface.